Certain diacetyl-amino-phenolic derivatives

Abstract

There is described a process for the production of a 1,4-dihydro-4-oxo-quinoline-2-carboxylic acid, or a salt, ester or amide thereof, which comprises cyclization of a corresponding 2-aminobenzoyl pyruvic acid or an ester thereof, and if desired or necessary converting the resulting product to an appropriate salt, ester or amide thereof, or vice versa.

We claim: 
     
       1. A compound having the formula ##STR4## in which R 6  b and R 7  b together form a chain --COCH═C--(COOH)--O--, or a pharmaceutically acceptable salt or a lower alkyl ester thereof, or form the pair of groups --COCH 3  and --OM, respectively, Rg and R 8  b, which may be the same or different, each represent hydrogen, alkyl or alkenyl, the alkyl and alkenyl groups each containing up to eight carbon atoms, and   M is hydrogen or an alkali metal,   provided that when Rg is hydrogen, R 6  b is acetyl and R 8  b is hydrogen, then R 7  b is other than --OH.   
     
     
       2. A compound according to claim 1, wherein R 6  b and R 7  b form the pair of groups --COCH 3  and --OM. 
     
     
       3. A compound according to claim 2 which is 4,6-diacetyl-3-amino-2-propylphenol, or   4,6-diacetyl-3-ethylamino-2-propylphenol.